Epidermoid cyst of the fourth ventricle: diffusion-weighted and flair MR imaging findings.

Fourth ventricle epidermoid cysts are rare lesions, arising from epithelial remnants at the time of neural tube closure. They are well-defined CT hypoattenuated masses that resemble CSF on all conventional MR imaging sequences. We present a case of a pathological proven less common fourth ventricle epidermoid cyst with special emphasis on the use of FLAIR and EPI-DW imaging sequences in the diagnosis.